1. Field of the Invention
The present invention relates to a device for cleaning semiconductor wafers with a cleaning liquid, comprising a cleaning station with a plurality of rotating pairs of rollers which are arranged one behind another and to which the cleaning liquid is applied, each pair of rollers being formed by a top roller and a bottom roller. The semiconductor wafer is conveyed between the pairs of rollers, and there is a conveyor means for conveying the semiconductor wafer to and from the cleaning station. The invention also relates to a method for cleaning semiconductor wafers in which such a device is used.
2. The Prior Art
A device for cleaning semiconductor wafers is disclosed in EP-691,675 A1, for example.
It is an object of the present invention to provide improvements to the prior art.
The present invention relates to a device which has a conveyor means which provides a film of conveyor liquid on which the semiconductor wafer is conveyed, and a means for supplying a cleaning liquid to the top rollers in the form of a falling liquid which migrates over the top rollers.
More particularly, the present invention is directed to a device for cleaning semiconductor wafers with a cleaning liquid, comprising a cleaning station with a plurality of rotating pairs of rollers which are arranged one behind another and to which the cleaning liquid is applied; each pair of rollers comprising a top roller and a bottom roller, and the semiconductor wafer being conveyed between the pairs of rollers; and a means for supplying the cleaning liquid to the top rollers in the form of a falling liquid which migrates over the rollers; and a conveyor means for conveying the semiconductor wafer to and from the cleaning station, and having a film of conveyor liquid which is provided by the conveyor means and on which film of conveyor liquid the semiconductor wafer is conveyed.
The present invention also relates to a method comprising conveying a semiconductor wafer to and from a cleaning station on a film of conveyor liquid, and supplying a cleaning liquid to top rollers of the pairs of rollers in the form of a falling liquid which migrates over the top rollers.
More particularly, the present invention is directed to a method for cleaning a semiconductor wafer with a cleaning liquid in a cleaning station comprising arranging in a cleaning station a plurality of rotating pairs of rollers one behind another; applying a cleaning liquid to the plurality of rollers; supplying the cleaning liquid to top rollers of the pairs of rollers in the form of a falling liquid which migrates over the top rollers; and conveying the semiconductor wafer between said pairs of rollers, and conveying the semiconductor wafer to and from the cleaning station on a film of conveyor liquid.
The present invention allows optimum cleaning of the semiconductor wafer combined with a minimum consumption of the cleaning liquid. It ensures that the cleaning liquid acts uniformly and that contamination of the semiconductor wafer is prevented. While it is being conveyed between the pairs of rollers, the semiconductor wafer only comes into contact with the film of cleaning liquid on the conveyor means. Thus the wafer contacts the cleaning liquid, but does not contact the solid components of the cleaning device, which may damage or contaminate the semiconductor wafer. The cleaning liquid is distributed uniformly over the semiconductor wafer, so that each surface of the semiconductor wafer undergoes the same treatment. Hence, a plurality of semiconductor wafers can be treated in succession in the same way. Further advantages of the invention are given in the following description, which is based on figures. The figures show only those features which contribute to a better understanding of the invention. Identical features are denoted by the same reference numerals.